Device for bending sheet metal into cylindrical shapes



April 25, 1950 w H MANN ET Al.

DEVICE OR'BENDING SHEET METAL INTO CYLINDRICAL SHAPES Filed Oct. '7,1948 2 Sheets-Sheet l W. H. MANN ET AL DEVICE FOR BENDING SHEET METALINTO CYLINDRICAL SHAPES April 25. 1950 2 Sheets-Sheet 2 Filed Oct. '7.1948 27 *Il l' /Z//arffeyf Patented Apr. 25, 1950 DEVICE FOR BENDINGSHEET METAL INTO CYLINDRICAL SHAPES William H. vMann and Elmer V.Schmidt, Winona, Minn., assignors to Hossfeld Manufacturing Company,Winona, Minn., a corporation of Minnesota Application October 7, 1948,Serial No. 53,302

4 Claims.

Our invention relates to improvements in metal ybending devi-ces and,more particularly, for bend-y ing sheet metal into cylindrical shapes.

An object of this invention is to provide a `simple and highly eiicientdevice for bending sheetrnetal into cylind-rical shapes, such asbushlvings of a size smaller than can be bent on conventional bendingrolls.

Another object of this invention is to provide `a device that will bendstock right up to the end,

"after the bend is Compared.

' A further object of this invention is to provide a device, by the useof which, cylinders of various different diameters can be bent simply bythe use of interchangeable mandrels of different diameter.

These and other objects of the invention will be` apparent from thefollowing detail description and the accompanying drawings.

To the above end, generally stated, the invention consists of the noveldevices and combination of devices hereinafter described and defined inthe claims.

Inthe accompanying drawings, which illustrate the invention. likecharacters indicate like parts throughout the several views.

Referring to the drawings:

- Fig. 1 is a plan view of the bending device; A Fig. V2 is a sideelevational view of the same, some parts` sectioned on the line 2--2 ofFig. 1;

Fig. 3 isa fragmentary detail view partly in plan and partly in` sectiontaken on the line 3-3 of Fig. 2, on an enlarged scale;

- Fig. 4 is aview partly in side elevation and partly in section takenon the line 4-4 of Fig. 3;

Fig. 5 is a plan view of the die removed from the stationary and bendingframes, the mandrel being removed from the center pin which is shown bymeans of broken lines; and

Fig. 6 is a perspective view of a cylinder formed on the mandrel.

The numeral 1 indicates a stationary frame comprising upper and lowerduplicate flat bars 8 and 9, respectively. These bars 8 and 9 areintermediately connected by a. spacing member I0 and a nut-equipped boltI I. Rearwardly o1 the spacing member l0, the bars 8 and 9 are inwardlyoffset to reduce the distance therebetween and are connected by frontand rearspacing sleeves I2 and nut-equipped bolts I3. The-frame 1 issupported on a pair of leg brackets M bolted at I5 to a bench or othersupport, indicated by a single line i6. Formed in the bars 8 and 9,forwardly of the spacing members Ill, is a plurality of longitudinallyspaced holes I1.

A swinging lever-acting frame I8 extends between the frame bars 8 and 9,at the front end portions thereof. This swinging frame I8 comprisesupper and lower duplicate bars I9 and 20 that are identical with thebars 8 and 9. A short handle 2l extends between the contracted endportions of the bars I9 and 29 and is rigidly secured thereto bynut-equipped bolts 22. This handle 2 l takes the place of the spacingsleeves l 2 for the frame l. The bolt 23 corresponds to the bolt ll .andthe co-operating spacing member is not shown. Formed in the bars I9 and20 is a plurality of Vlongitudinally spaced holes 24 that correspond tothe holes l1. In the free end portions of the bars 8 and 9 is a pair ofaligned large holes 25 and a corresponding pair of large holes 26 areformed in the bars I9 and 20.

' The swinging frame i9 is connected to the stationary frame 1 by a pin27 that extends through a pair of the aligned holes ll and the pair ofthe aligned holes 24. This pin 21 has a head 28 that rests on the upperbar 3 and holds said pin suspended therefrom.

' The stationary frame 'i and the swinging frame :8 are not new butafford a highly eilicient device for the embodiment of our invention.

. Referring now in detail to our invention, to wit: a'die for formingcylindrical shapes from sheet metal which includes a vertically disposedbending block 29. This bending block 29 is rigidly secured to an uprightsleeve 39 by a pair of diverging plates 3l secured to the outer verticalportions of said bending block. The sleeve 3!! is pivotally secured tothe swinging frame i8 by a wrist pin 32 which extends therethrough. Theend portions of the wrist pin 32 are held in the first pair of alignedholes 24 offset from the pivot pin v2'I toward the handle 2|. The sleeve30 rests on the lower frame bar 29 and the wrist pin 32 extends betweenthe bars 8 and 9 and is held thereby against endwise movement.

The bending block 29 rests on and is rigidly secured to a U-shapedspacing and guide member 33 which slidably rests on the lower frame bar9. This member 33 is of the same thickness as the lower frame bar 29 onwhich the sleeve 30 and. side plates 3| rest. A center pin 34 extendsthrough the large holes 25 in the frame bars 8 and 9 and is supported atits lower end on a member 35 secured to the lower frame bar 9. Thiscenter pin 34 extends between the prongs of the spacing and guide member33 and holds said member for 3 straight line sliding movement on thelower frame bar 9.

A cylindrical mandrel 36 is removably mounted on the center pin 34. Asheet of metal .'12, partly bent to cylindrical form, is held pressedagainst the mand-rel 36 iby the two side members of the bendingblock 29at their outer Vertical end portions, which afford contact points 31.The metal sheet :c is shaped about the mandrel while held pressedthereagainst, by a multiplicityp short bends. The bends aremadeby'pulli-ng `the lever-acting swinging frame I3 toward thefcent'erpin` The rst operation in .bending the sheet :Il around the mandrel 36will bring the twoicon'tact points 31 of the bending Sblock 125ivvcontact with said sheet and bend the same between the two contactpoints 31 around the mandrel 36. Succeeding operations of theleveracting frame I8 will iirst move the bending block 29 yaway from themandrel 36 tov permit said sheet to be ifed by hand between. the contact.points 31 and thenmove the bending block 29 toward the mandrel '3S and,at which time, one of the -bending block contact points 31 engages thecurved portion of the sheet :c and holds the same pressed against 'themandrel 36 and the other contact :point 431 engages an unbent portion ofthe sheet :z: and bends the same around the mandrel 36. 'Theseoperations -ar-e repeated until the sheet :c

is bent into cylindrical 'formt' and removed from theimandrel 3S, seeFig. 6. During the operation fof the bending block 29., the lil-shapedmember V33 is guided by the center pin 34 for straight-line 'movementand holds lthe bending block 29 .-for

faction `on the sheet x being bent. By the short llift the center pin313 to Withdraw the same from the mandrel, substitute another mandrel ofa vdifferent external diameter therefor, ,place the same on the guidingand spacing member 33 in alignment with the center 'pin 3E and drop saidpin 'through the replaced mandrel, between the vprongs of the member 33,through the hole 2'6 in 'the lower frame bar 9 and onto'the stop member35.

l The drawings illustrate a commercial form of 'the invention, but itwill be understood that the 'same is capable of certain modificationsa's to Adetails fo'f construction, arrangement and combi- `nation lfofparts within the scope lof 'the `invention Vherein disclosed.

In Vactual use of What we claim is:

1. In a die of the class described, a stationary frame, a lever-actingmember pivoted to the frame, a center pin on the frame, a removablecylindrical mandrel on the center pin, a V-shaped bending blockVhayii'ig side lmembers arranged to .press a sheet kof metal onto themandrel at circumferentially spaced points, a wrist pin on thelever-acting member, a sleeve on the wrist pin, and a pair of sideplates rigidly secured to the sleeve, said side plates being indiverging relation from the sleeve to receive the bending blocktherebetween, said -side plates being rigidly secured to the sidemembers of said bending block.

2. The combination with a stationary frame having upper and lower bars,a swinging frame having upper and lower bars extending transverselybetween 'the iirst noted bars and pivoted thereto, 'of a die includinga. center pin mounted in aligned holes in the bars of the stationaryframe, a cylindrical mandrel4 on the center pin, a V-,shaped bendingblock having side `members arranged to press a lsheet of metal onto theman,- drel `at circumferentially spaced points, 'a wrist pin mounted inaligned holes in the 'bars of the swinging frame, a sleeve on the wristpin, anda pair of side plates rigidly secured. to the sleeve, said sideplates being in diverging relation from the sleeve to receive the.bending .block therebetW-een, said side 'plates being rigidly secured tothe side members of the bending block.

3. rIhe 'structure dened in claim .2, further including a spacing andguide member on the lower end of the spacing block and loosely restingon the lower. bar of the stationary frame and having a slot 'throughwhich the center pin extends.

4. The structure defined in Vclaim 2,"further including Aa U-shapedspacing and 'gui/de member 'on the lower end of the bending block, thetransverse portion of said member extending transversely under 4the sideplates and straddling the ycenter pin.

WM. H. vELMER. V. SCHMIDT.

REFERENCES CITED 1 The following references are of record inthe file ofthis patent:

UNITED STATES PATENTS Number Name Date 247,004 Benedict Sept. 13, 1881l421,019 Taylor `Fe'b. 11,1890 869,107 Shults Oct. 22, 1907 n1,523,594'Hoss'feld Jan. 20, 1925 1,622,806 Papke Mar. 29, V1027 1,968,645Hossfeld July 31, l19321 '12,415,143 f 'I-Iossfeld Feb. l1, 1947

